Subject: C5e) Why don't we try to destroy tropical cyclones by cooling the
surface waters with icebergs or deep ocean water ?

Contributed by Neal Dorst (HRD)

Since hurricanes draw their energy from warm ocean water, some
proposals have been put forward to tow icebergs from the arctic
zones to the tropics to cool the sea surface temperatures. Others
have suggested pumping cold bottom water in pipes to the surface,
or releasing bags of cold freshwater from near the bottom to do this.

Consider the scale of what we are talking about. The critical
region in the hurricane for energy transfer would be under or
near the eyewall region. If the eyewall was thirty miles (48
kilometer) in diameter, that means an area of nearly 2000 square
miles (4550 square kilometers). Now if the hurricane is moving
at 10 miles an hour (16 km/hr) it will sweep over 7200 square
miles (18,650 square kilometers) of ocean. That's a lot of
icebergs for just 24 hours of the cyclone's life.

Now add in the uncertainty in the track, which is currently
100 miles (160 km) at 24 hours and you have to increase your
cool patch by 24,000 sq mi (38,000 sq km). For the
iceberg towing method you would have to increase your lead
time even more (and hence the uncertainty and area cooled)
or risk your fleet of tugboats getting caught by the storm.

For the bag/pipe method you would have to preposition your
system across all possible approaches for hurricanes. Just
for the US mainland from Cape Hatteras to Brownsville would
mean covering 528,000 sq mi (850,000 sq km) of ocean floor
with devices.

Lastly, consider the creatures of the sea. If you suddenly cool
the surface layer of the ocean (and even turn it temporarily
fresh), you would alter the ecology of that area and probably
kill most of the sea life contained therein. A hurricane would
be devastating enough on them without our adding to the mayhem.